Large panels for use with vehicles such as aircraft or watercraft my be reinforced using stiffeners such as Z-, C-, I-, J-, hat, or blade stiffeners in order to hold their shape under the various loads presented to them during operation. These panels may comprise three-dimensional contours to which the stiffeners must be coupled. Current methods of making tooling (e.g., mandrels) for use in generating stiffeners for coupling to three-dimensional contours are not well adapted to form the stiffeners into discrete, complex three-dimensional shapes needed for use with the vehicle panels (e.g., large aircraft wing skins) as the tooling has typically been formed of metal or other stiff materials, making the tooling difficult to create or use (and even impossible to use in the case of certain stiffeners).